1. Field of the Invention
The present invention relates to a controller for a photographing apparatus and a photographing system with a high operational characteristic and a high visibility suitable for a photographing operation of the apparatus that is disposed at a remote place and that is used for a monitoring operation, an observing operation, a guiding operation, a presenting operation, and so forth.
2. Description of the Related Art
As shown in FIG. 23, when the user controls a photographing apparatus disposed at a remote place, he or she operates a pan tilter in eight directions (up, down, left, right, upper right, lower right, upper left, and lower left directions) with eight-direction keys, a zooming controller, and a wide-angle controller so as to photograph a desired object while observing a photographed picture 6A on a monitor 2. In the structure shown in FIG. 23, the user moves a cursor 7 to one of the direction keys 10 with a mouse 8. Alternatively, after the user has controlled a photographing apparatus disposed at a remote place in the above-described method and registered pan tilter information and zoom information of positions of pictures to be photographed, he or she drives the photographing apparatus at absolute positions corresponding to the registered positions so as to select pictures.
In the conventional controller, a picture that is displayed on the monitor is limited in the range of which the photographing apparatus is moved by the pan tilter. Thus, when the user photographs a desired object, he or she should operate the pan tilter in the full range thereof. Consequently, the user should have skill in operating the pan tilter.
When the user changes the photographing direction with the conventional direction keys, even if he or she stops pressing the direction keys, since the pan tilter does not immediately stops and thereby he or she may not catch a desired object. When the direction varying speed of the photographing apparatus with the pan tilter is low, although such a problem may be solved, since the response characteristic deteriorates, a high operational characteristic cannot be obtained.
When the user wants to place a desired object at the center of the angle of view of the photographing apparatus, since he or she controls the photographing direction while observing a picture on the monitor, he or she should determine the photographing direction on trial and error basis. Thus, the user may spend a long time for controlling the photographing apparatus. Moreover, to properly operate the photographing apparatus, the user should have skill.
When picture and control information is exchanged with a photographing apparatus disposed at a remote place through a low-capacity network, the control information may be lost and/or picture information may be delayed due to an irregularity of their arrival intervals. If the pan tilter or the zooming controller is operated for picture and control information that has been delayed or lost, even if the user causes the pan tilter and the zooming controller to place the object at the desired position, the pan tilter and the zooming controller do not properly operate. Thus, the object is placed at an improper position due to the delay. In addition, depending on the line condition, the arrival intervals of picture information vary. Thus, the user should control the pan tilter and the zooming controller based on a prediction. Consequently, the user cannot properly control the pan tilter and the zooming controller.